Nail fixed in the Temple

(of Jupiter). On September 13th a nail was annually
driven into the wall of the temple of Jupiter. This was originally done
to tally the year, but subsequently it lapsed into a religious ceremony
for warding off calamities from the city. Originally the nail was
driven in the wall by the praetor maximus, subsequently by one of the
consuls, and lastly by the dictator. (See Livy, vii. 3.).